How fast do left atrial (LA) myxomas grow? To attempt to answer this question we examined publications describing patients in whom myxoma recurred in the left atrium after earlier excision of a similar tumor from this chamber. Although many publications have described recurrence of myxoma in the left atrium after previous operative excision, most did not provide either the weight or the dimensions of the myxoma excised at the second operation (1-14). At least 10 publications (9 patients) have described either the dimensions or weight of a recurrent myxoma in the left atrium and these 9 cases are summarized in Table I (15-24). Of the 7 patients where the information was provided, the largest dimension of the recurrent LA myxoma ranged from 1.5 to 10.0 cm (mean 5.1), and the interval from the first operative excision to the operation for excision of the recurrent LA myxoma ranged from 11 to 76 months (mean 33). Thus, the recurrent myxoma in these 7 patients increased in size an average of 0.15 cm a month or 1.8 cm a year between the 2 operations. In 3 of the 9 patients with recurrent LA myxoma, the weight of the recurrent tumor was provided: the recurrent tumor weighed 19, 30 and 58 g and the interval between the 2 operations was 24, 30 and 36 months, respectively. Thus, the recurrent LA myxoma in these 2 patients grew an average of 1.2 g a month or 14 g a year.